Gas burner for soaking pit furnaces and the like



Aug' 7 1.951 T. w. I Ewls 2563683 GAs BURNER FOR soAKING PIT FURNACESAND THE LIKE `Filed Feb. 7, 1946 i "HNR l lllllul wml INVENTORZ HisATTORNEY.

Patented Aug. 7, 1951 GAS BURNER FOR SOAKING PIT FURNACES AND THE LIKEThomas W. Lewis, Munhall, Pa., assignor to United States Steel Company,a corporation of New Jersey Application February 7, 1946, Serial No.646,157

1 Claim. 1

This invention relates to improvements in burners for the combustion ofhydro-carbonaceous fuels for heating soaking pit furnaces and the like.

In some types of bottom-fired soaking pit furnaces, the fuel, such ascoke oven gas, is supplied thereto from a vertical pipe through a portcentrally located in the bottom of the heating chamber. Surrounding thefuel pipe, there is provided an annular column of preheated air whichprovides oxygen for delayed combustion, and forms a long flame whichrises to the top of the chamber where it is deflected outwardly anddownwardly to pass between and around the ingots on the furnace hearth.The products of combustion exit from the chamber through ports locatedjust above the hearth and are then passed through heat exchangers, suchas recuperators, to preheat the incoming air. From the foregoing, it isseen that the efficiency of the furnace depends on the thoroughness withwhich the air and gas are mixed.

Accordingly it is an object of this invention to provide a burner forsoaking pit furnaces and the like which permits more efficient operationof the furnace.

It is a further object to provide a burner for soaking furnaces whichefliciently mixes the fuel and preheated air and by causing a maximum ofturbulence, produces a flame of maximum luminosity and temperature.

The foregoing and further objects will become apparent from thefollowing specification when read in conjunction with the attacheddrawing, wherein:

Figure l is a vertical section showing the burner. port and a portion ofthe hearth of a bottom-fired soaking pit furnace;

Figure 2 is an enlarged plan view of the burner; and

Figure 3 is a sectional elevation taken on line III-III of Figure 2.

Referring more particularly to the drawing, the numeral 2 designates abottom-fired soaking pit furnace having a hearth 4 with a centrallylocated port E therein. Heated air from suitable recuperators or heatexchangers (not shown) is supplied to the relatively large port 6 andburner 8 disposed therein through conduits I which are used alternately.Fuel is supplied to the burner through a pipe I2.

The burner 8 of my invention is disposed at the upper end of pipe I2 sothat it is centrally located in the port 6. The burner consists of ahollow cap I4 in the form of an inverted frustum of a cone having aclosed lower end I6, the upper end of which is iiush with the end of thepipe I2. The cap I4 is welded or otherwise secured to the pipe and has aplurality of vertical elongated slot-shaped openings i8 suitably spacedaround the sloping sides thereof. The

slope of the sides and the openings are arranged to permit convergingstreams of gas to pass through the cap and meet at the center and nearthe top of the cap. The size and shape of the openings I8 is such thatthe maximum velocity of the streams for the required fuel rate isobtained. Due to the increased fuel velocity and, by the impinging ofthese gas streams one on another at the point of convergence, a greatturbulence and breaking up of the gas streams is produced prior tomixing with the air supply thus effecting more intimate and effectivemixing which in turn produces greater combustion efficiency and resultsin a flame of greater luminosity and temperature.

This burner and method of preheating the gaseous fuel prior to mixingwith the air supply has resulted in a saving of two to three hours inthe time required to heat ingots.

While I have shown and described one specific embodiment of myinvention, it will be understood that this embodiment is merely for thepurpose of illustration and description and that various other forms maybe devised within the scope of my invention. as defined in the appendedclaim.

I claim:

In combination, a furnace which includes'a chamber having a bottom wallformed with a port, conduits underneath said chamber for supplyingpreheated air to said port, and a pipe extending into said port andterminating below said chamber for supplying gaseous fuel thereto; aburner which comprises a cap mounted in the exit end of sald pipe andbeing in the shape of an inverted frustum of a cone having a closedbottom and sloping side walls, said bottom being disposed interiorly ofsaid pipe, said sloping side walls having a plurality of pairs ofoppositely disposed openings of elongated outline with their elongateddimensions being in the direction of slope of said side Walls, wherebysaid openings direct streams of gaseous fuel issuing therefrom underpressure to a point of convergence at the center line of the pipe nearthe top of the cap.

THOMAS W. LEWIS.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 502,710 Ferguson Aug. 8, 18932,297,696 Elder Oct. 6, 1942 FOREIGN PATENTS Number Country Date 23,217Great Britain of 1903 19,073 Great Britain of 1914 106,654 SwitzerlandOct. 16, 1924

